Here's 2 subjects/event ideas that I wish Science Olympiad had (I haven't really browsed this thread too much, so these might have already been stated):
1. An event where you had to do some computer programming to solve or do something as quickly as you can (like, finish programming it before your competitors, not how fast the program runs), and the points are given by how effectively it handles or solves the situation, and how fast it took to make it. Frameworks and libraries will be provided and/or listed by the invitational leaders, and browsers are disabled, so no copying code off the internet; it's all from you! I think you should be allowed to bring in 2 doubled sided sheets of paper, as remembering how programs work isn't too challenging.
2. I'd really enjoy an event on cryptanalysis; the study of encryption and how it works. Maybe having an event to solve or analyze how something was encrypted and decrypt it before your competitors do via the use of some tools and allowing the teams to bring in a binder full of information to help them. Not really too sure about how it'd work though.
... in my opinion.
Thanks for reading my post. :D